Thiophosphoric acid esters and process for their manufacture



THIOPHOSPHORIC ACID ESTERS AND PROCESS FOR THEIR MANUFACTURE GerhardSchrader, Wuppertal-Cronenberg, Germany, assignor to FarbenfabrikenBayer Aktiengesellschaft, Le-

verkusen, Germany, a corporation of Germany No Drawing. Filed Dec. 2,1957, Ser. No. 699,935 Claims priority, application Germany Dec. 21,1956 2 Claims. (Cl. 167-33) The present invention relates to and has asits objects thiophosphoric acid esters of the general formula in which Rstands for lower alkyl radicals, especially such in which R, R R R andalk have the same significance as described above.

Suitable for this reaction are generally tertiary amines that means inwhich none of R R and R are hydrogen.

R R and R together with N may also form a hetero-- cyclic nucleus ofaromatic nature such as pyridine.

The reaction may be carried out with'or without using suitable inertsolvents. The reaction largely depends upon the nature of the tertiaryamine used to carry out this reaction. Pyridine needs temperatures, sayup to about 60 to 90 C.

The compounds of the present invention are easily water-soluble and thusmay be used in aqueous solutions as contact insecticides and systemicagents for the control of pests. Some of the new compounds are also ofinterest as pharmaceutical products on account-of their highlyphysiological action. Most of the compounds are strong cholinesteraseinhibitors. The new pesticides may be used in the same manner as otherknown phosphoric insecticides, i.e. in a concentration from about0.0000l% to about 1%, diluted or extended with suitable solid or liquidcarriers or diluents. Examples of such solid carriers are talc, chalk,bentonite, clay and the like, as liquid carriers there may be mentioned,water (if necessary with commercial emulsifiers, which however in mostcases is absolutely unnecessary, because of I 2,980,581 PatentedApr'flfi i ice or methyl ethyl ketone, liquid hydrocarbons and the like.

The new compounds may furthermore be used in combination with each otheror with known insecticides, tertilizers etc.

As an example for the special utility of the inventive compounds thecompound of the following formula has been tested against spider mitesand caterpillars. Aqueous solutions have been prepared by simplydissolving the compound in water to a concentration as indicated below.The tests have been carried out as follows:

(A) Against spider mites, Tetranychus altaeae, V. Hanst, (two spottedspider), on Phaseolus vulgaris plants which have been sprayed to the runoff by the aqueous emulsions as prepared above. 1

(B) Against caterpillars of Plutella cruciferarum, Zell, (diamond backmoth), on young plants of white cab bage which have been sprayed withthe above prepared aqueous dilutions to the run oil.

Killing efiect in each case has been determined after 24 hours. Thefollowing results have been obtained: spider mites were killedcompletely with solutions of 0.01% and caterpillars were killedcompletely with 0.1%

solutions.

The following examples are given by way of illustration only withoutlimiting the present invention thereto:

ester of the following formula S OCaHB formula O OCzH Br- OCrHI 2. Aprocess for combating insects which comprises v4 1 2,980,581 p A 3treating said insects with a compound corresponding to the followingformula:

0 OCaHu References Cited in the file of this patent UNITED STATESPATENTS FOREIGN PATENTS 665,315 Great Britain Ian. 23, 1952 Fitch Nov.3, 1959 Belgium May 17, 1954 OTHER REFERENCES Renshaw et a1.: I. Am.Chem. Soc., vol. 51, page 954 (1929).

Ghosh et al.: Chem. and Ind., Jan.'29, 1955, page 118.

Tammelin: Acta Chem. Scand. 11, pages 1340-1349 (August 1957).

Koelle et al.: J. Pharmacol. Exper. Therap., vol. 118, p. 421 (December1956).

Leopold et al.: A.M.A. Archives of Ophthalmology," 58, pp. 363-366(September 1957).

1. THE THIOPHOSPHORIC ACID ESTER OF THE FOLLOWING FORMULA 